55555...55557 (88-digits)
This number is a prime.
55555555 5555555555
5555555555 5555555555 5555555555 5555555555 5555555555 5555555555 5555555557
The largest near-repdigit prime p smaller than a googol
found in the sequence 7, 57, 557, 5557, 55557, 555557,
5555557, etc. Curiously, p is also expressible as the sum
of two squares. [Bajpai]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell